TEST METHOD FOR ORTHOPHOSPHATES IN INDUSTRIAL WATER (RANGE: 0-100 mg/L PO4)
BACKGROUND OF THE TEST:
Since orthophosphates are extensively used for boiler water treatment. Consequently optimum
residual phosphates are ensured to maintain in the boilers as per an appropriate standard or boiler
manufacturer recommendation.
Nuclotrasis offers user friendly test method with ease of handling the relevant reagents and other
equipments used in the analysis. For determination of residual phosphates in a boiler,
molybdovanadate method is widely used. This test relies on Lambert Bear’s Law of spectrometry
where orthophosphate are allowed to react with molybdate in an acid medium to produce a mixed
phosphate/molybdate complex and in presence of vanadium, yellow molybdovanadophosphoric
acid is formed. The intensity of the yellow color is proportional to the concentration of phosphate
in a particular sample. The measurement wavelength is 430 nm for spectrophotometers or 420 nm
for colorimeters.
REAGENTS/EQUIPMENTS/APPARATUS:
Provided 10 mL marked glass vial (Item Code: 02-01)
Any Suitable Spectrophotometer
Relevant Cuvette or cell of Photometer
NUCLOTRASIS ORTHOPHOSPHATE TEST SOLUTION (Item Code: 01-02)
SAMPLE COLLECTION & PREPARATION
Make sure to immediately analyze the sample after collection of sample.
Ensure to collect sample in a suitable and designated bottle for a specific sample.
Ensure to conduct this test at room temperatures.
TEST PROCEDURE:
1. Take sample to 10 mL mark into the provided vial (Item Code: 02-01) and call it as “A”.
2. Similarly take 10 mL deionized water in another cuvette or test tube for reagent blank and
call it as “B”.
3. In the sample, add 20 drops (1 mL) NUCLOTRASIS ORTHOPHOSPHATE TEST SOLUTION
(Item Code: 01-02) and mix gently.
4. Allow to stand for ten (10) minutes for full color development.
5. Meanwhile, select Orthophosphate or phosphate specific channel/test in the
spectrophotometer.
6. First run reagent blank “B” to achieve blanking.
7. Then run test sample “A” and note the Photometer display reading in µg/L or mg/L. In case
photometer is not available, match the developed color with the provided soft copy color
comparator of this PHOSPHATE HR test kit.
8. Multiply the reading with dilution factor 1.1.
REFERENCES:
ASTM D 515-82, Phosphorous in Water, Test Method C